Update on TN50X81 Toshiba convergence tripping shutdown.

With datasheet for PCM56P DAC ICs, I see why I'm not getting all the signals, some partials, some totally off and some are flatlined, only two out of six were outputting correct signals for convergence amp ICs. All six of DAC ICs are getting data, clock and enable signals from T7K64 IC with own EEPROM.

Do I go with replacing PCM56P DACs or this T7K64 IC (SMD square IC)?

Do anybody else see high failure rate on PCM56P ICs it is DAC by burroughs brown.

Cheers, Wizard

Reply to
Jason D.
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Just a shot, but have you tried powering up the set with the convergence outputs disconnected and then entered the convergence service mode and performed an all reset to default settings to reinitialize the eeprom? If the eeprom somehow became corrupted, this might fix the problem.

Also is the convergence module getting all the correct signals from the mainboard?

FYI: Toshiba's replacement part is the entire convergence module and that was what we always replaced. They required it under warranty as the early versions had an engineering defect and needed modified.

Jas> With datasheet for PCM56P DAC ICs, I see why I'm not getting all the

Reply to
dkuhajda

Good point, problem is I don't have service manual and getting it is has to figure into estimate which will jack up from 300+ to over 450+ and may scare customer off. Do you have steps or info to send to me by email to do the convergence job or reset?

Yes, it is, communicates via serial bus ATE, data and clock. and one I2C.

Ooh. What is the early and late version of this module part numbers on it so I can tell apart on one I have now.

Cheers, Wizard

Reply to
Jason D.

Looks like you need the service manual. I don't have access any longer. Back in 2002 I was full aware of the problems Toshiba was having with the convergence modules in those sets, and they were paying for a lot of out of warranty replacements at that time. I was probably doing 1 or 2 per week with this failure for about 1.5 years back 3-4 years ago.

You did not answer the question of whether it was getting all the correct signals. I2C and data buses and power is only part of it, what about the pulses from the vertical and horizontal circuits?

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The tz50v51 service information should give you the basics on getting into the convergence mode and doing a reset, if your set has additional screen modes 480p, widescreen, etc, you will need the full service manual on how to get into each mode to adjust the convergence.

FYI if this fixes the problem, you also need to buy the screen overlay (or make one) for each mode to do the geometry adjustments. Same would go if you could have replaced the main PLC/EEProm ic in the module. I am not even sure you can buy that part from Toshiba individually, certainly buying it generically won't work as it won't have any of the programming information preloaded.

This is one set that it would probably be much less expensive having a Toshiba Warranty authorized servicer repair as they should already have all the overlay jigs and service manual on hand. This is your first Toshiba RPTV from that era with a convergence module issue? Given the high failure early on, I would bet that any Toshiba authorized servicer that does any kind of volume for them has all the jigs and information.

Reply to
dkuhajda

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