CurtPalme.com Home Theater Forum

Luuk neele · Posted: Wed Mar 18, 2015 11:57 pm Post subject:

cr35 is on, cr39 blinks, they do go out after a little while.
(also the +12 and +5v lights are on too)

there are no bent pins on the vertical deflection board

mac · Joined: 07 Nov 2012 Posts: 143

Well that all looks fine so I would have to assume a vert board problem.

Luuk neele · Posted: Thu Mar 19, 2015 12:51 am Post subject:

its late (or early) im going to sleep, tired of fiddling with the ampro.
if you have ANY idea, please dont hesitate

mac · Joined: 07 Nov 2012 Posts: 143

Probably have to troubleshoot it. Post here tomorrow if that is something you want to do.

Luuk neele · Posted: Thu Mar 19, 2015 1:04 am Post subject:

He'll yes, I'm now bent on getting this puppy working
Plus it keeps me off the streets.
So where do we start? Smile

mac · Joined: 07 Nov 2012 Posts: 143

Luuk neele · Posted: Thu Mar 19, 2015 10:15 am Post subject:

hey i am back once again, now lets fix this sweep problem on the ampro.
where do we start?

mac · Joined: 07 Nov 2012 Posts: 143

Well first thing you are going to have to do is test the supply voltages. I am sure you do not have an extender card so you will have to connect small wires at various location, put the board back in so you can turn on the projector to test. The wire can be really small as long as it is insulated. There are a bunch of places that need to be tested so you can either do them 1 at a time or connect a bunch of wires all at once, tape them to a piece of cardboard and mark where each one came from.

DMM should be on DC voltage, chassis should be fine for ground.

Locate the following test points on the vert board and connect wires, tests voltages and give me the readings.

TP11
TP12
TP13
TP14
TP15

Luuk neele · Posted: Thu Mar 19, 2015 2:51 pm Post subject:

got a load of pc wires for that, the TP points are the little orange things where i loop the wire through, so thats going to be easy. the worst part is that i do not have an oscilloscope, or this would be much easier.

how much DC voltage goes through there? just so i know in which range to measure.

mac · Joined: 07 Nov 2012 Posts: 143

All are under 20v.

Luuk neele · Posted: Thu Mar 19, 2015 9:02 pm Post subject:

mac · Joined: 07 Nov 2012 Posts: 143

recheck TP15

Luuk neele · Posted: Thu Mar 19, 2015 10:10 pm Post subject:

mac · Joined: 07 Nov 2012 Posts: 143

Pull the board out and do a continuity test from that tp15 to ic21 pin 3 and see if it shows short. If yes then check the part number on that ic and give it to me.

Luuk neele · Posted: Thu Mar 19, 2015 10:25 pm Post subject:

mac · Joined: 07 Nov 2012 Posts: 143

Hmmmm, my schematic does not call for a 7905 there. Does it look like it was ever changed?

Luuk neele · Posted: Thu Mar 19, 2015 10:45 pm Post subject:

yes, theres flux on the backside, it has definitely been changed.

mac · Joined: 07 Nov 2012 Posts: 143

I have a vert board here somewhere. Let me grab it and check. In the meantime do a couple more continuity tests so we can verify.

Locate ic11. Should be an 8 pin ic. Do a continuity test from TP13 to pin 8 on the ic.

Then do TP15 to pin 5 on ic11.

See if the results of both tests show dead short. Meanwhile I'll get that board here.

Luuk neele · Posted: Thu Mar 19, 2015 11:15 pm Post subject:

mac · Joined: 07 Nov 2012 Posts: 143

Yeah, I got same results here. And yes, that is the wrong part in there. It should be a 7915. Do you have any parts around or do you have to order it?