CurtPalme.com Home Theater Forum

[helfriwj]

I figured out that the error code is 02 When I reset the power and clear the code then start the projector the fans turn on and then the projector turns off with error code 02. The error code listing says that it is ( H stop ) 115 V down what board could this be traced to I do have spare 1292 projectors one works and the other does not I also have a spare E board assembly any help would be great
Thanks
Bill

[mack1]

Your best bet would be to PM Graham Johnson.He is the 1292 god.Do a search here on the forum for his address

[Graham Johnson]

Looks like it has a board fault.

One thing you could try is checking the big transistor in the bracket that is bolted on the front of the power supply. Its been a while but I think that creates an 02 error code if dead.

If that isnt it. Looks like you will be board swapping for a solution.

[helfriwj]

I tried swapping the power supply with no change I then swapped out the E and DC boards and that fixed the problem I have three 1292 projectors and this is the third time that the faults were fixed by changing out the E and DC boards anyone know what components on these boards would cause this problem since I only have one set left.

[Curt Palme]

I can repair them if you want. I have a test chassis here. I can't see why you're having that many problems with the same boards though, that's not typical for a 1292.

[Curt Palme]

I can repair them if you want. I have a test chassis here. I can't see why you're having that many problems with the same boards though, that's not typical for a 1292.

[paulk2]

I don't have boards to swap, but I did check the main power supply voltages and they're OK, then checked DC supplies to the PA board (where the h-stop line goes to), all OK, then checked waveforms on tp1 and tp2 - OK, then the waveforms on Q201 (the external HV Out transistor mounted on the chassis).

The waveform at the base of Q201 was perfect and at the collector it was good on frequency, amplitude and duty cycle but had a 125v offset for about half of the off-cycle. The waveform in the manual did not show this 125v offset. Is this significant (considering the circuit is simply supposed to be generating a huge 800v horizontal waveform)?

Should I be looking through the E and DC boards (as in the previous posts)?

Any common failures that would trigger 02 would be appreciated.

Thank you,

Paul

[macgyver655]

You need to check your 115v line.

[paulk2]

Hi,

Thank you for the pointer. The 115v supply on the PA board is 115.1v. The +15, -15 and +12v supplies are good too. The waveforms are as described above.

If I disconnect CN284, where the H-stop line comes in, the set will stay on without shutting down and that gives me a chance to hit MENU on the remote to see if anything comes up on the diplay - nothing. I shut down after 10 sec.

It sounds like HV is coming up with a slight static crackle. I don't have a HV probe for my meter, darn it. I gently reseated connectors on several boards and the CRT's.

Please let me know what other information I need to provide.

Thank you for your help!

Paul

[macgyver655]

Without having boards to try and verify just which board the problem is on then your going to have to do some hunting. If it was me I think I would be looking on the E board. Your 115v detection and H stop is on that board. I would start by checking Q115,Q7, Q8, Q116, Q117 and Q145. There is also a Horizontal size protection circuit on there. Have you increased the raster size? You could try backing off RV104 a little on that same board and see if it responds.

[macgyver655]

Oh, and check pin 1 on ic 115 on the E board for 115v. That is the 115v line detect ic.

[paulk2]

This is GREAT information! Thank you!

So far, voltages around IC115 look good. I will gather more information and post later today.

Thanks again!

Paul

[paulk2]

More information -

IC 115 - dc voltages normal; pin 1 output is low (0v) to "115v on" status line (CN131 pin 9), so I presume 0v on this line means 115v is present (which it is).

starting at h-stop switch and working backwards...

Q115 - H stop switch - E=0(gnd), B=.4v (should be 11.3), C=4.6v (should be 0v). Apparently Q115 is turned off because IC117 output is low.

[Interesting that the load from the voltmeter on the base of Q115 causes the stop switch to deactivate and leave the projector on. disconnecting CN284 from PA board has same effect. useful if you need an extra second or two for things to stabilize or to separate cause from shutdown ckt, and are willing to take a damage risk.]

IC117 input has no signal (should be 11.6vpp horiz) from Q116 and Q117.

Q116/Q117 - DC at Emitters is low .13v (.7v expected) base is .2v - OK; no waveform at base.

Q118 DC voltages OK. no waveform at gate (driven from a separate output of T102, horiz out xfmr).

Q7 - E=.16v (should be -13.3), B=-.25 (should be -14.1), C=.11 (should be -.8). I presume the DC voltages are shut down because it derives them from the oscillation. I can't do a DC check on Q7 or Q8 (or many of the nearby diodes) because of the low resistance values surrounding them and they're hard to take out. I could clip a lead or two if they are still suspect.

Q8 - similar DC voltages except base has a small horiz waveform for 1/2 sec, then system shuts down. If I disable system shutdown, the waveform still goes away. waveform is 2Vp-p, should be 7.5vp-p.

Q145, 146 and 147 drive T104/103/106 (which drives Q7 and Q8), so I looked at them.
Q145 - G=4v(expected 3.4)w/10vp-p horiz square wave (hooray! we found some oscillation!), Drain=39.9 (expected 67) 90vp-p horiz waveform, S=gnd
Q146 - B=39.9vdc (expected 67) w/90v waveform from Q145, C=gnd, E=40.1v (expected 67.1)
Q147 - E=40vdc (expected 67) w/60vp-p waveform (should be 120vp-p as in waveform #5), C=74vdc (should be 109), B=40vdc (should be 67)

Since the emitter of Q147 drives one side of T103/104/106's primary winding, I looked at Q148 which anchors the other side of the winding.
Q148 - E=30vdc, B=40vdc, C=.12vdc no waveforms present or listed, although I would expect some hint of horiz because it's pulling against the drive of Q147 which does show a waveform. Q148 passes a quick in-circuit DC voltage drop test .62v

other measurements: actual(expected)

Q102 E/B/C 12.1/11.4/12.07 all ok
Q107 E/B/C .68(2.1) no waveform #8/.97(2.2)/12
Q108 E/B/C 0 (2.1) no waveform #8/.3 (1.6)/0
Q109 S/D/G .3(1.6)/0 gnd/-.24(-.2)
Q132 E/B/C 11.3(11.7)/10.7(11.2)/1.1(1.3) all ok
Q133 E/B/C 3.3(3.4)/1.2(1.3)/12.1 all ok
Q134 E/B/C 3.3(3.4)/3.85(3.9)/10.7(11.2) all ok
Q135 E/B/C 0/.11/12.2 all ok
Q136 E/B/C .01/.11 no waveform #4/-.01
Q137 E/B/C 8.21(4.2)/8.8(4.8)/45(107.8)
Q138 E/B/C 3.78/4.36/12.2 all ok
Q139 E/B/C 12/11.38(0)/8.8(4.8)
Q140 E/B/C .46(2.7)/0(.5)/11.4(0)
Q141 E/B/C .45(2.7)/.12(0) no waveform #6/12.2(12)
Q142 S/D/G -.02(0)/113.7(116.1)/-.02(0)
Q143 E/B/C 113(110.4)/74(111)/75.1(115.4)
Q144 E/B/C 40.1/75.1(110.4)/113(115.4)



CN103 pin 3 "HD +12V"=.03v not sure if this is a cause or effect.

[paulk2]

Oh, you asked about raster size being changed - it has not been touched (perhaps never) so I left it alone.

Thank you!

Paul

[macgyver655]

Ok, now your just giving me a head ache with all those numbers......

One thing at a time and forget the scope for now.

IC115..pin1.........connect a volt meter to it and gnd. Turn projector on and you should have 115v. What do you have?

[paulk2]

IC115 pin 1 is 0v. The 115v supply is working.

Sorry about the flood of data.

Paul

[macgyver655]

0v on pin 1 should be fine even though it should be 0.1v.

Have you checked those xsistors I listed for shorts between legs?

Funny thing is.......Curt is probably up there in winter wonder land, chuckling...... and going.....na na na na na...I know what the problem is and you guys aren't even close.......

[macgyver655]

Ok, I just went over your findings and you are on a good track. I'm thinking you need to see if you have 12v coming out of ic118. If not do you have +15.5 coming in? Might as well check ic116 while your at it for the same.

[paulk2]

No shorts on the transistors you listed, although Q7 and Q8 are hard to check bacause they have 100 ohm resistors around them. If they are shorted, it's above 100 ohms. I can cut the leads to isolate and check them if they are strong contenders. I'm guessing that the fault lies upstream of the horiz drive transformers near Q148 because it's not pulling against Q146/147, who appear to be doing their job.

Q146/147 - half size waveform, but the best one available. Q148 - no waveform --> drives Horiz drive xfmrs --> Q7/Q8 (tiny waveform at Q8).

IC118 is good (it supplies Q133 collector in the voltages listed above)
IC116 is good (it supplies Q102 emitter in the voltages listed above)

Next...? or should I clip Q7 and Q8 for an isolated DC check?

Curt? can we tempt you to comment?

Thank you!

Paul

[macgyver655]

So you have +12v @ pin 16 on ic117?

You wont get curt to comment. Actually this conversation has went to far as to forum edicate.

[mikeshole]