That was a lot of great info -- thanks. But what is the "diagonal strap across tube?" -- Scott--- On Thu 12/29, Hans O < p1001@wideopenwest.com > wrote:From: Hans O [mailto: p1001@wideopenwest.com]To: vectorlist@vectorlist.orgDate: Wed, 28 Dec 2005 23:21:03 -0600Subject: Re: VECTOR: troubleshooting G08-003 monitor - HELPYou're on the right path. Missing or insufficient deflection shuts down the HV. Recapping the monitor is a good idea. (Beware that all the G08 cap kits I've used were supplied with an incorrect cap in the voltage doubler circuit(C401?). Original is 1000uf/80v but kits had 1000uf/50v. Best to leave original or find a 100v). I don't have a print so I'll ramble off my head a bit...Dumb question, does your board set work? Yes? Good. So with good input to the G08, you get no HV. No HV points to no deflection in either direction, X or Y. You've tested the deflection transistors and they're good (not shorted to ground either, right?). Fuses F600 and F700 are
good? Time to go over those pesky connectors. Reflow and check tension on the female ends.Jump next to the power circuit. Test that all the appropriate DC voltages are present, +63, -63, +9.1, -9.1, +55, +125?. All good?Jump back to the deflection circuit and test the discreet components, especially MPSU10's and 60's. Looks for burnt, open, loose, or missing traces. Again, cap kit is a good idea. Might have to take transistors out to test. Keep your eye out for incorrect components or ones installed backwards. I've only found one bad custom IC 600 so I can't be sure of what the symptoms are when they do go bad. Perhaps another can shed some light. Now it's time to fire it up again. Hopefully you've got picture.Partial deflection, i.e. horizontal collapse but vertical is OK, monitor usually will still work. Work your way through the corresponding deflection circuit until you lose the signal.My check list of G08 culprits:Concentrate on the deflection board and transistor
assemblies.Connectors, connectors, connectors. Yes, reflow all headers.Loose or bent contacts on female half of connectors, especially the vertical "paddle" boards.Caps dry, shorted or popped.Deflection transistors, usually blown.Semiconductors in X any Y circuits. Best to test out of circuit.You'll find lots of transistors from previous repairs in place of MPSU10's and 60's. Most do not work.Bad custom IC 600. No known fix except to find another.Loose, rusted, or simply missing diagonal strap across tube.Strong points...Rarely a bad HV unitRarely a bad neck boardWhen you do finally repair it, share your find with us.Hans O in Chicagoeyeamnomad@excite.com wrote:> > > Okay, thanks for the advice. This is my first attempt at repairing> any kind of videogame or monitor, and I am somewhat of a neophyte to> all of this, so I am grateful for all of your help! I was trained as> an Electronics Technician in the Navy long ago, but I never did much> of that kind of
work after the schooling. I'm a little rusty. The> closest thing to a videogame I ever worked on was the AN/PDR radar> set they had at ET school. Nuclear power is more my thing. But I> digress.> > I have done continuity checks on all the connectors, and they all> indicate 0 ohms. The deflection xistors are definitely fine.> > I am getting a fluctuating reading at the pins that lead to the> deflection coils (like, +/- 20VDC, which isn't +/- 63V, but my DMM> isn't that fast). So that seems to be fine. However, I'm getting DC> voltages at pins 9 and 10 on the HV unit connector that are about> half of what the FAQ/vector monitor guide say I should get (it says> 2.8 & 3.5; I'm getting about 1.5 & 2.5).> > If I understand correctly, the X and Y signals coming to the HV unit> feed IC 900. If IC 900 doesn't get an adequate X or Y signal, it> shuts down the flyback transformer. Is that right? This would seem> consistent
with my initial readings -- the only voltages I couldn't> get were the ones that are generated by the transformer (400VDC for> focus and brightness control, 6.3VAC for cathode heater).> > Therefore, I'm guessing that since the signals are half the normal> strength, that's enough to prevent the HV from kicking on. I can't> find any bad components in the deflection circuitry or the current> limiting PCB's, so I guess my next step is to replace all the caps> -- I already have a couple of Zanen cap kits, I just haven't> bothered using them yet -- and to clean the pins/reflow solder on> connectors, as Mr. Hanlon suggested. Does that make sense?> > I hope that does the trick; it will take at least another day or two> to do all that. I'll let you know what happens. I'll entertain any> other ideas!> > - Scott Slaughter> > > ------------------------------------------------------------------------> Join Excite! -
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Received on Sun Jan 1 18:51:43 2006
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