Return to the CurtPalme.com main site CurtPalme.com Home Theater Forum
A forum with a sense of fun and community for Home Theater enthusiasts!
Products for Sale ] [ FAQ: Hooking it all up ] [ CRT Primer/FAQ ] [ Best/Worst CRT Projectors List ] [ Setup Tips & Manuals ] [ Advanced Procedures ] [ Newsletters ]

 
Forum FAQForum FAQ   SearchSearch   MemberlistMemberlist  Photo AlbumsPhoto Albums  RegisterRegister 
 MembershipClub Membership   ProfileProfile   Private MessagesPrivate Messages   Log inLog in 
Blu-ray disc release list and must-have titles. Buy the latest and best Blu-ray titles to show off in your home theater!


Marquee Modifications and Performance Enhancement
Goto page Previous  1, 2, 3 ... 10, 11, 12 ... 62, 63, 64  Next
 
Post new topic   Reply to topic   Printer-friendly view    CurtPalme.com Forum Index -> CRT Projectors
View previous topic :: View next topic  
Author Message
rpruen



Joined: 07 Apr 2008
Posts: 67
Location: Southwest UK

TV/Projector: BD701 FTS, BD808s


PostLink    Posted: Wed Jul 30, 2008 6:57 pm    Post subject: Reply with quote


        Register to remove this ad. It's free!
I have a quick question, as it relates to replacing resistors on my Barco as well....

Do you have to take care when replacing carbon comp resistors with metal oxide/metal film? In high frequency circuits, the metal resistors will have a much greater inductance than the carbon due to the construction.

In some cases it's going to help, where the resistor is in a filter trying to keep RF out of a part of a circuit, the inductance would increase the impedance to the RF. If the resistor is trying to pass RF, then the opposite will happen and the inductance will get in the way of the signal.

I'm not sure if it will make any real world difference, but theoretical it should. It may be the frequencies are low enough that it doesn't matter, but at 100MHz?

Sorry to hijack the thread, but the people who know may well be reading.

Thanks

Richard
Back to top
Nashou66



Joined: 12 Jan 2007
Posts: 16170
Location: West Seneca NY


PostLink    Posted: Wed Jul 30, 2008 7:20 pm    Post subject: Reply with quote

rpruen wrote:
I have a quick question, as it relates to replacing resistors on my Barco as well....

Do you have to take care when replacing carbon comp resistors with metal oxide/metal film? In high frequency circuits, the metal resistors will have a much greater inductance than the carbon due to the construction.

In some cases it's going to help, where the resistor is in a filter trying to keep RF out of a part of a circuit, the inductance would increase the impedance to the RF. If the resistor is trying to pass RF, then the opposite will happen and the inductance will get in the way of the signal.

I'm not sure if it will make any real world difference, but theoretical it should. It may be the frequencies are low enough that it doesn't matter, but at 100MHz?

Sorry to hijack the thread, but the people who know may well be reading.

Thanks

Richard


Richard no problem joining in with a good question. The carbon Comps should not be replaced with metal film as to the reasons you mentioned as I understand(I am not an EE either ! ). They should be replaced with either Carbon Film, Ceramic, and I believe Metal Oxide as these are not a wound metal resistor, its a composition of metal and ceramic I think? have to do some research on them. Any one else have more to add?

Athanasios

_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher


"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan

One Smart Dog!!!

Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
Back to top
View user's photo album (1 photos)
rpruen



Joined: 07 Apr 2008
Posts: 67
Location: Southwest UK

TV/Projector: BD701 FTS, BD808s


PostLink    Posted: Wed Jul 30, 2008 8:48 pm    Post subject: Reply with quote

Nashou66 wrote:

Richard no problem joining in with a good question. The carbon Comps should not be replaced with metal film as to the reasons you mentioned as I understand(I am not an EE either ! ). They should be replaced with either Carbon Film, Ceramic, and I believe Metal Oxide as these are not a wound metal resistor, its a composition of metal and ceramic I think? have to do some research on them. Any one else have more to add?

Athanasios



The trouble is that I trained as an EE, it's just I haven't done much RF stuff for a long time. In fact I haven't done much in the way of component level repair for a bit.

I'll look into this, but as far as I remember, carbon comp, and ceramic are the only ones with effectively no inductance. All the film resistors have a spiral etched (or burned with laser) into the resistive material, so are going to have some inductance. They have a ceramic core, so the inductance will be very small. The resistive material will also change the inductance, so carbon film may be lower than metal film, for example.

As to the question of if it actually matters to the insides of our projectors, I don't know. I can find out if needs be, but thought I'd ask the question.

Richard
Back to top
Nashou66



Joined: 12 Jan 2007
Posts: 16170
Location: West Seneca NY


PostLink    Posted: Wed Jul 30, 2008 9:08 pm    Post subject: Reply with quote

rpruen wrote:
Nashou66 wrote:

Richard no problem joining in with a good question. The carbon Comps should not be replaced with metal film as to the reasons you mentioned as I understand(I am not an EE either ! ). They should be replaced with either Carbon Film, Ceramic, and I believe Metal Oxide as these are not a wound metal resistor, its a composition of metal and ceramic I think? have to do some research on them. Any one else have more to add?

Athanasios



The trouble is that I trained as an EE, it's just I haven't done much RF stuff for a long time. In fact I haven't done much in the way of component level repair for a bit.

I'll look into this, but as far as I remember, carbon comp, and ceramic are the only ones with effectively no inductance. All the film resistors have a spiral etched (or burned with laser) into the resistive material, so are going to have some inductance. They have a ceramic core, so the inductance will be very small. The resistive material will also change the inductance, so carbon film may be lower than metal film, for example.

As to the question of if it actually matters to the insides of our projectors, I don't know. I can find out if needs be, but thought I'd ask the question.

Richard


From previous post on the "A" site archives where JeaHong lee repoerted using Ceramics vs the carbon comps in the HVPS and the Video Neck Boards's there was discussion on this topic. Mike Parker says not to use Metal Film but carbon film is ok. I think Metal/oxide may be different for the LVPS though where high voltages are not as high as the HVPS and the VNB's. I think they talked about High voltages causing magnetic fields if you use metal Film I couldnt find it in the thread link I'll post but it was somewhere in my research for this thread;

JeaHong Lee's thread on VNB resistors change

I'm Glad your joining us here!! I could use another EE on board to help me with testing procedures with A scope I got that I only used a few times to solve my Focus Board Problem.
I'll look up some info on the meatal Oxide as I do not think they have any windings and are more like the Ceramic resistors of the resistive material just mixed with sand or ceramic granuals.

Athanasios

_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher


"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan

One Smart Dog!!!

Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
Back to top
View user's photo album (1 photos)
htguy1



Joined: 30 Jul 2008
Posts: 99



PostLink    Posted: Wed Jul 30, 2008 9:17 pm    Post subject: things to keep in mind... Reply with quote

Hi,

Some other things to keep in mind when adding/replacing parts...

Adding bigger uf caps can lead to to much current draw at startup as all the caps try to charge at once and can overload the LVPS (Been there, done that, took them off and got it working again Wink

Also with inductors, they also "hold" a charge if you will and they will release the charge once the circuit colapses at power down, so be careful not to go bigger than needed as it increases the risk of damaging things on power down. (As I understand it, its like the (back to the damn illistration) water keeps hitting the damn in the certain speed the damn stops and it builds up. The Capacitor to ground helps drain this off, but there is still some charge left and when you power the system off, there is no more water pushing against the damn, so what is piled up there bounces back off the damn, creating a wave back up the "river"

God bless...

Mark
Back to top
rpruen



Joined: 07 Apr 2008
Posts: 67
Location: Southwest UK

TV/Projector: BD701 FTS, BD808s


PostLink    Posted: Wed Jul 30, 2008 10:17 pm    Post subject: Reply with quote

Quote:
From previous post on the "A" site archives where JeaHong lee repoerted using Ceramics vs the carbon comps in the HVPS and the Video Neck Boards's there was discussion on this topic. Mike Parker says not to use Metal Film but carbon film is ok. I think Metal/oxide may be different for the LVPS though where high voltages are not as high as the HVPS and the VNB's. I think they talked about High voltages causing magnetic fields if you use metal Film I couldnt find it in the thread link I'll post but it was somewhere in my research for this thread;


That's some interesting reading. And yes the resistor subject is covered a little. Though it's not that clear.
I'll do a little research of my own. There are lots of types of resistor.

Quote:
I'm Glad your joining us here!! I could use another EE on board to help me with testing procedures with A scope I got that I only used a few times to solve my Focus Board Problem.
I'll look up some info on the meatal Oxide as I do not think they have any windings and are more like the Ceramic resistors of the resistive material just mixed with sand or ceramic granuals.

Athanasios


Well I'm happy to help out if I can. Let me know what you wanted to do, and I'll try to sort out something. I have a BD701FTS that I can mess with, as it is not my primary projector any more.

A scope is possibly the most useful thing you can have, there is just so much you can do with it, from simply testing voltages (like a multimeter), to seeing how a barco input board mashes the signal, to some of the crazy waveforms that come out of the convergance driver board. The list is endless....

More on resistors....

The metal oxide resistors I was thinking of are the laser trimmed type, as you say a film deposited on a ceramic susbstrate, and baked to provide a resistance value near to the required one, other stuff is included in the mixture to 'dilute' the metal oxide and increase the resistance when needed. The film is then cut with a laser to trim the value to within tolerance.

The sort of resistor you are talking about sounds like a thin film resistor, this has a pure metal oxide layer deposited on it in a vacuum, so is much better (lower noise, lower inductance, less temperature drift). It is still trimmed with a laser to set the value, but since the process is better, less trimming is required.

I'll get a selection and try them out in my projector when I get the chance. I'm guessing that the ceramic type will be best 'bang for buck' in most situations, as they are almost like a carbon comp, but with lower noise.
Back to top
tse



Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.


PostLink    Posted: Thu Jul 31, 2008 1:39 am    Post subject: Reply with quote

The main reason for using the carbon comp resistors is their ability to take a surge and not change value. A surge can occur when there is a HV arc. Many times a film resistor will open (increase value) when hit with a big current during an arc where the solid carbon core of a carbon comp resistor will remain intact. That is why you see them on neck cards and in HV power supplies.

Scott

_________________
"Were we directed from Washington when to sow and when to reap, we would soon want bread."

Thomas Jefferson
Back to top
Nashou66



Joined: 12 Jan 2007
Posts: 16170
Location: West Seneca NY


PostLink    Posted: Thu Jul 31, 2008 1:49 am    Post subject: Reply with quote

tse wrote:
The main reason for using the carbon comp resistors is their ability to take a surge and not change value. A surge can occur when there is a HV arc. Many times a film resistor will open (increase value) when hit with a big current during an arc where the solid carbon core of a carbon comp resistor will remain intact. That is why you see them on neck cards and in HV power supplies.

Scott


I know this should be the case but on my HVPS when I measured the Carbon comps they all opened from 560 to 680 and some 730. I replaced them with the 560 ceramics but noticed that the tubes would still be lit a bit while showing only one tube by useing the color mute feature. So i raised the Ceramic value to the average of the carbon comps and things are back to normal and no problems with G2 voltages as they are now with in spec. This was dicussed by a few other members last year, here in the states and over seas and those who have raised the value to what the old carbon comps actually measured had the same results. So it seams after time they did drift but at the same time it seams the drift value became what the PJ liked? it is weird but thats what mine and others findings were. what would your take on it be? Why would the wrong values be the right ones in the end?

Note: only the carbon comps in the HVPS read far off the VNB ones meassured ok

Athanasios

_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher


"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan

One Smart Dog!!!

Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
Back to top
View user's photo album (1 photos)
rpruen



Joined: 07 Apr 2008
Posts: 67
Location: Southwest UK

TV/Projector: BD701 FTS, BD808s


PostLink    Posted: Thu Jul 31, 2008 7:13 am    Post subject: Reply with quote

tse wrote:
The main reason for using the carbon comp resistors is their ability to take a surge and not change value. A surge can occur when there is a HV arc. Many times a film resistor will open (increase value) when hit with a big current during an arc where the solid carbon core of a carbon comp resistor will remain intact. That is why you see them on neck cards and in HV power supplies.

Scott


That's a good point, the same reason for using them in antenna systems, where (distant) ligtning causes very short large overloads.

In that case the ceramic resistors should be the better choice, since there is more thermal mass. So more ability to absorb short overloads. The are still less noisy than the carbon comp type.

Thanks for that

Richard
Back to top
rpruen



Joined: 07 Apr 2008
Posts: 67
Location: Southwest UK

TV/Projector: BD701 FTS, BD808s


PostLink    Posted: Thu Jul 31, 2008 7:56 am    Post subject: Reply with quote

Nashou66 wrote:
I know this should be the case but on my HVPS when I measured the Carbon comps they all opened from 560 to 680 and some 730. I replaced them with the 560 ceramics but noticed that the tubes would still be lit a bit while showing only one tube by useing the color mute feature. So i raised the Ceramic value to the average of the carbon comps and things are back to normal and no problems with G2 voltages as they are now with in spec. This was dicussed by a few other members last year, here in the states and over seas and those who have raised the value to what the old carbon comps actually measured had the same results. So it seams after time they did drift but at the same time it seams the drift value became what the PJ liked? it is weird but thats what mine and others findings were. what would your take on it be? Why would the wrong values be the right ones in the end?

Note: only the carbon comps in the HVPS read far off the VNB ones meassured ok

Athanasios


That seems a bit odd. Given years of running at high temps the resistance could change, and they start out with a fairly poor tolerance. I would guess that something in the circuit is adjusted to match the resistor. Having everything drift in the right direction by chance, that's a bit much Smile

It may be that the manufacturing process uses a test jig on the board, and a few resistor values are calculated so as to put everything in spec. These parts would be soldered into the board as the last step. Automotive ECUs used this quite a bit, particularly early on. Though if this was the case then those resistors must have been 'way out' from the day the board was made.

If the neck board resistors are very close to the rated value, then that is a bit odd too, as you would expect some variation due to tolerances. It's possible that the resistors are measured and the 'close to rated value' ones are used in critical locations, and the 'not so close' are used in less critical ones. It's the same as matched transistors, they are sorted by measurement in a test jig, into matching pairs, triples, quads, and etc.

Richard
Back to top
Nashou66



Joined: 12 Jan 2007
Posts: 16170
Location: West Seneca NY


PostLink    Posted: Thu Jul 31, 2008 10:45 am    Post subject: Reply with quote

rpruen wrote:
Nashou66 wrote:
I know this should be the case but on my HVPS when I measured the Carbon comps they all opened from 560 to 680 and some 730. I replaced them with the 560 ceramics but noticed that the tubes would still be lit a bit while showing only one tube by useing the color mute feature. So i raised the Ceramic value to the average of the carbon comps and things are back to normal and no problems with G2 voltages as they are now with in spec. This was dicussed by a few other members last year, here in the states and over seas and those who have raised the value to what the old carbon comps actually measured had the same results. So it seams after time they did drift but at the same time it seams the drift value became what the PJ liked? it is weird but thats what mine and others findings were. what would your take on it be? Why would the wrong values be the right ones in the end?

Note: only the carbon comps in the HVPS read far off the VNB ones meassured ok

Athanasios


That seems a bit odd. Given years of running at high temps the resistance could change, and they start out with a fairly poor tolerance. I would guess that something in the circuit is adjusted to match the resistor. Having everything drift in the right direction by chance, that's a bit much Smile

It may be that the manufacturing process uses a test jig on the board, and a few resistor values are calculated so as to put everything in spec. These parts would be soldered into the board as the last step. Automotive ECUs used this quite a bit, particularly early on. Though if this was the case then those resistors must have been 'way out' from the day the board was made.

If the neck board resistors are very close to the rated value, then that is a bit odd too, as you would expect some variation due to tolerances. It's possible that the resistors are measured and the 'close to rated value' ones are used in critical locations, and the 'not so close' are used in less critical ones. It's the same as matched transistors, they are sorted by measurement in a test jig, into matching pairs, triples, quads, and etc.

Richard



Thanks for your input Richard! You may be right about the test jig, but they do have a few trim pots on the HVPS, maybe they put the parts in and if the Carbon comps were out of spec from the get go they adjust those pots to get the intended design outcome. that is why when some of us put in the speced part value it was wrong because the parts were out of spec in the begining. And the the ones on the neck board they may have payed closer attention to the actual measured spec of the part since no trim pots are in the design for that circuit. Also the HVPS was made not by electrohome but subed out to Spellman who may not have had the tme to mesure each part going in and aded the pots for conveinience.

Athanasios

_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher


"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan

One Smart Dog!!!

Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
Back to top
View user's photo album (1 photos)
rpruen



Joined: 07 Apr 2008
Posts: 67
Location: Southwest UK

TV/Projector: BD701 FTS, BD808s


PostLink    Posted: Thu Jul 31, 2008 5:37 pm    Post subject: Reply with quote

Nashou66 wrote:

Thanks for your input Richard! You may be right about the test jig, but they do have a few trim pots on the HVPS, maybe they put the parts in and if the Carbon comps were out of spec from the get go they adjust those pots to get the intended design outcome. that is why when some of us put in the speced part value it was wrong because the parts were out of spec in the begining. And the the ones on the neck board they may have payed closer attention to the actual measured spec of the part since no trim pots are in the design for that circuit. Also the HVPS was made not by electrohome but subed out to Spellman who may not have had the tme to mesure each part going in and aded the pots for conveinience.
Athanasios


If there are trim pots then that is more than likely it. The trim pots are there to adjust the output of the board to meet specification, and would allow for parts to be used with a wider tolerance. Things like transistors can have quite a wide range of HFE (the amount of amplification), as well as the resistors, and every other part on the board.

Automotive ECUs tend not to use trim pots due to vibration, and the like. Not an issue with a projector (well not so much).

I would guess that is it, the final test of the board on a test jig would simulate the operation of the board, and the trim pots would be adjusted to put the measured values within the specification.

If you can figure out what trim pots need to be adjusted, then you could tweak the settings, so that the correct resistor values work. That may improve things, as the circuit will be closer to how it was designed. However the change may be too small to make any real difference, or it may not change the operation at all. Looking at the drawings may help to figure out if that would be worthwhile.

After all that the easiest idea may be to replace the resistor with one of the same value as measured. That is what you have done already.

Richard
Back to top
Nashou66



Joined: 12 Jan 2007
Posts: 16170
Location: West Seneca NY


PostLink    Posted: Thu Jul 31, 2008 6:09 pm    Post subject: Reply with quote

rpruen wrote:
Nashou66 wrote:

Thanks for your input Richard! You may be right about the test jig, but they do have a few trim pots on the HVPS, maybe they put the parts in and if the Carbon comps were out of spec from the get go they adjust those pots to get the intended design outcome. that is why when some of us put in the speced part value it was wrong because the parts were out of spec in the begining. And the the ones on the neck board they may have payed closer attention to the actual measured spec of the part since no trim pots are in the design for that circuit. Also the HVPS was made not by electrohome but subed out to Spellman who may not have had the tme to mesure each part going in and aded the pots for conveinience.
Athanasios


If there are trim pots then that is more than likely it. The trim pots are there to adjust the output of the board to meet specification, and would allow for parts to be used with a wider tolerance. Things like transistors can have quite a wide range of HFE (the amount of amplification), as well as the resistors, and every other part on the board.

Automotive ECUs tend not to use trim pots due to vibration, and the like. Not an issue with a projector (well not so much).

I would guess that is it, the final test of the board on a test jig would simulate the operation of the board, and the trim pots would be adjusted to put the measured values within the specification.

If you can figure out what trim pots need to be adjusted, then you could tweak the settings, so that the correct resistor values work. That may improve things, as the circuit will be closer to how it was designed. However the change may be too small to make any real difference, or it may not change the operation at all. Looking at the drawings may help to figure out if that would be worthwhile.

After all that the easiest idea may be to replace the resistor with one of the same value as measured. That is what you have done already.

Richard


I would rather not mess with those, TSE and Tim Martin have said to leave them alone, so I think the measuring of the old resistors and averaging the value from the 6 that were in there was the right way to go as I have been running it this way for at least 8 months with no issues and great results.

Athanasios

_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher


"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan

One Smart Dog!!!

Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
Back to top
View user's photo album (1 photos)
rpruen



Joined: 07 Apr 2008
Posts: 67
Location: Southwest UK

TV/Projector: BD701 FTS, BD808s


PostLink    Posted: Thu Jul 31, 2008 6:20 pm    Post subject: Reply with quote

Nashou66 wrote:

I would rather not mess with those, TSE and Tim Martin have said to leave them alone, so I think the measuring of the old resistors and averaging the value from the 6 that were in there was the right way to go as I have been running it this way for at least 8 months with no issues and great results.

Athanasios


Yep as I say the gains would be small or non existant, so doing the swap as you have is way easier. Unless you have the factory test jig, there is always the option of blowing something to bits tweaking trimpots.

Richard
Back to top
PaulB



Joined: 26 Oct 2007
Posts: 359
Location: Bonnie (but rainy) Scotland


PostLink    Posted: Wed Aug 20, 2008 6:17 pm    Post subject: Reply with quote

I sat down to look at the CLM decoupling caps over the weekend and tried to figure out the + and - end for a single cap, X30, using the schematics and looking at the CLM.

I can see from the schematic that X30 is on the +5 volt rail and that it is connected to U30, so far so good. X30 appears to be attached to pin 11 (or A0 ? ) on the schematic (which does confuse me as I would have said its pin 22 counting from the left side of the chip but anyway, its attached regardless of the pin number). However, looking at the schematic for U30, the power rail looks as if its coming from pin 23?

Piccie of X30 and U30



The problem I'm having is that I expected to see X30 attached directly to the +5 rail leading to U30 and looking at it, I'd say the positive end of X30 is the end nearest U30 BUT, looking at the schematics I'm just not understanding whats going on here. I would have thought that the +5 came through X30 and out to U30 but thats not how I'm reading the schematics which to me looks like the power comes OUT of U30 and IN to X30 (which would mean that the positive side of for the X30 tant would be on the side furthest away from U30?)? Basically, I'm lost, again, totally Sad

Edit - I just re-read this and I can't even figure out what it is I'm trying to say, thats how confused I am!

PS - What camera do you use Athanasios? Mine is just pants at taking close-ups, complete and utter pants!

_________________
Paul
Back to top
David_Web



Joined: 02 May 2007
Posts: 418
Location: Sweden


PostLink    Posted: Wed Aug 20, 2008 6:44 pm    Post subject: Reply with quote

Are you sure X30 has polarity?
Isn't polarity normally signified by a line at one end. Like C7 (that has a + beside it even)

I looked at the schematic and now my head hurts too.

_________________
SNR of people are ridiculously low.
Back to top
Nashou66



Joined: 12 Jan 2007
Posts: 16170
Location: West Seneca NY


PostLink    Posted: Wed Aug 20, 2008 6:49 pm    Post subject: Reply with quote

All of those caps are decoupling caps, they go from pin to ground, depending on if it a chip that gets power from a + And a - or just one decides how the caps will go, they filter the power to ground for that chip which may be + or -. You need a pin out diagram of each chip if you do it that way. that be a pain but its a safe way to make sure the + goes to the + pin or - to the - pin of that specific chip.

If you take your multi meter and set it to continuity, as you should already be doing when doing the cap mods on this board !!, you put one end on the first large caps + or - side that "feed" the smaller caps. then you put the other end of your multi meter to one side of the pad your putting a new cap on, if you have the + side of the large cap like C3 ,that feeds that series of chips/caps, and put the other end of the meter on a pad and it beeps you have the + side for the new cap.

its that simple but very time consumming but also very nessasary. i have poped a few tants along the way with no damage to any chips but i guess i was lucky and it can possibly do damage and fixing a CLM is very hard.

Athanasios

_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher


"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan

One Smart Dog!!!

Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal


Last edited by Nashou66 on Wed Aug 20, 2008 7:01 pm; edited 1 time in total
Back to top
View user's photo album (1 photos)
Nashou66



Joined: 12 Jan 2007
Posts: 16170
Location: West Seneca NY


PostLink    Posted: Wed Aug 20, 2008 6:50 pm    Post subject: Reply with quote

David_Web wrote:
Are you sure X30 has polarity?
Isn't polarity normally signified by a line at one end. Like C7 (that has a + beside it even)

I looked at the schematic and now my head hurts too.


thats the difficulty of this mod, your adding polarity caps to locations that used non polar ceramics.

Athanasios

_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher


"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan

One Smart Dog!!!

Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
Back to top
View user's photo album (1 photos)
Nashou66



Joined: 12 Jan 2007
Posts: 16170
Location: West Seneca NY


PostLink    Posted: Wed Aug 20, 2008 7:03 pm    Post subject: Reply with quote

Maybe i will try to take a full pic of all the caps so you can use it as a refrence. if it doesnt show enough detail i wont post it.

I am doing Antorsea's clms now, i forgot how long this upgrade takes Shocked

Nashou

_________________
Don't blame your underwear for your crooked ass~ unknown Greek philosopher


"Republicans believe every day is the Fourth of July, but the Democrats believe every day is April 15." --- President Reagan

One Smart Dog!!!

Marquee High Performance Bellows now shipping!!
Marquee Modifications and Performance Enhancement
Marquee C-element and Bellow removal
Back to top
View user's photo album (1 photos)
PaulB



Joined: 26 Oct 2007
Posts: 359
Location: Bonnie (but rainy) Scotland


PostLink    Posted: Wed Aug 20, 2008 7:48 pm    Post subject: Reply with quote

I understand the concept of using the continuity check but had thought that it wasn't reliable after you posted the warning about sometimes not being able to nail it due to the cap switching thing. If using the continuity check is indeed a bit hit and miss then my not understanding the schematics will just compound any problems I may (or may not!) run in to.

I do get the idea of what I need to do and how to do it but the schematics (partiularly when looking at the likes of U30) just aren't registering with me - I can however see exactly what you are saying about C3 and the +5 rail to the decouplers.

If you could post pics of a modded board then that would be of immense help, even if its posted in sections or something. A single hi-res maybe? Sorry my friend, I know I'm a pain.

I must say that I'm very pleased that David_Web chimed in, its reasurring that I'm not the only one that gets confused with this! Thanks Dave, you've cheered me up no end! Thumbs Up

Nashou66 wrote:

I am doing Antorsea's clms now

Nashou


What???? Favoritisim, thats what that is! What about the rest of us? Mine is in the post...........!












Mr. Green

_________________
Paul
Back to top
Display posts from previous:   
Post new topic   Reply to topic   Printer-friendly view    CurtPalme.com Forum Index -> CRT Projectors All times are GMT
Goto page Previous  1, 2, 3 ... 10, 11, 12 ... 62, 63, 64  Next
Page 11 of 64
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum