>>> Got a 57H93 HD Toshiba top end 2003 set in for service and it's DEAD.
>>>> No LED no power on click, there is a click of the relay when plugging
>>>> in the set (normal). Problem is in the MPU obviously. Checked and
>>>> voltages, reset, clock, read of cust info mem IC, reset of scine
>>>> module, but no activity on the serial data line to or from the scine
>>>> module from the MPU, clock is there. And no clock and data from
>>>> Gemstar to Scine (digital board) Tech docs say that this indicated bad
>>>> module but that info was for a powered on set. If I understand
>>>> correctly gemstar and digital board are always on and can talk to
>>>> external devices even when main power is off. So that should mean bad
>>>> module, SCINE (digital) and Gemstar should be replaced together docs
>>>> say.
>>>>
>>>> Best guess is that the main mpu is looking for the digital (scine)
>>>> module to talk to it before it will fully initialize and accept a power
>>>> on command. The digital module gemstar boards are to be replaced as a
>>>> set and the part $904 is NLA no longer available. Part #23148064
>>>> (SHU152 and PD1540)
>>>>
>>>> Three year old set to be thrown away...I find that exceedingly stupid.
>>>>
>>>> Same part (function) on a Hitachi $384, on a Samsung $300.
>>>>
>>>> I'm hoping that I missed something and this part is available at a
>>>> reasonable price.
>>>
>>> Have you checked PTS to see if they have rebuild boards or will rebuild
>>> the ones you have? There is also a 23148064X which may be available.
>>> What distributors are you using?
>>>
>>> Leonard
>> Checked Tritronics and PTS, Tritronics lists part as NLA and PTS has no
>> listing for that part in orig or "X" flavor, as rebuildable or stocking
>> module. I'd also like to find out if my guess is correct. Can't get any
>> more info unless you are a "Authorized service center".
>>
>> Also, no service info for the digital module, "It's to be repaired at
>> modular level", yeah right NLA.
>>
>> Anyone have a XXH93 that's suffered a cabinet or tube failure...in other
>> words available to be parted out.
>
> Have Tritronics talk to Toshiba and get clarification. They will do the
> research for you and see if the X version is available or if they will be
> getting more of them. I have run into several long term backorders with
> Toshiba in the last couple of years...DCUs, Hyper Modules, and FBTs.
>
> You might try posting on sci.electronics.repair, the TechData forum, or
> the TechAssist listserve. Someone on one of those might have a scrapper
> but I doubt it. Probably the only reason one of those would be trashed at
> this point would be the same reason you have.
>
> Have you isolated everyting else on the data bus(es)? See if things start
> coming up? Usually not much detail on the communication between chips in
> many sets these days, so sometimes you just have to divide and conquer...
>
> Sounds like you have all the documentation, right?
>
> Leonard
I think I have all the documentation, and you are right...can't tell what the MPU is looking for, no documentation on it's internal logic.
On previous chassis (H83) there was no ATSC digital module with the scine circuitry. The MPU didn't have the extra serial data port that talks only to the digital board. There were two serial data lines that talked to other processors in the set and even if the serial data line was blocked by being held low or high the MPU would boot and indicate by flashing the power on led it's status and sometimes what circuit had the problem. That was a useful feature. It seems that feature was not implemented for the data line to the digital board and it's so critical that they have no recovery option if the digital board doesn't talk to the MPU. The last is a guess.
As for the digital module, there is no documentation for that and the serial data line between the gemstar module and digital (scine) board is dedicated. My only hope is to check the digital board for obvious problems internally like power and data lines critical to the main controller in the digital board.