|
Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
|
Thread Tools |
26th Mar 2023, 11:19 pm | #1 |
Pentode
Join Date: Mar 2010
Location: Ipswich, Suffolk, UK.
Posts: 136
|
Sanyo TPM-2170 Mini TV / Alarm Clock / Radio
Just bought this little thing on eBay on a whim, and from the moment I took it out of the box I was smitten! It's the cutest little thing!
The seller claimed the unit was working until they accidentally reversed the polarity on the power supply, after which it stopped working. I would really, really love to get this thing working - it's such a gorgeous little thing - but I'm not sure whether reversing the power supply polarity would have done catasrophic damage. I found the circuit diagrams, and there doesn't appear to be any reverse polarity protection. The -ve of the power supply is connected directly to ground, so in a reverse-polarity scenario, that would obviously have become +ve, which I'm thinking could have had far-reaching consequences. Worryingly, the unit is not totally dead. It shows signs of life:
Having looked inside the unit, it looks like a bit of a nightmare to disassemble to even gain access to the main TV PCB (where the power supply is located). Is it worth even trying to fix, or is it likely to be a lost cause after suffering a reverse polarity power connection? |
27th Mar 2023, 8:58 am | #2 |
Pentode
Join Date: Apr 2021
Location: Paris, France.
Posts: 235
|
Re: Sanyo TPM-2170 Mini TV / Alarm Clock / Radio
Hi trellis,
I would first have a look to the power supply part (voltage regulation), it's possible that damages are limited to this part, especially the semiconductors. Last edited by marceljack; 27th Mar 2023 at 9:15 am. |
27th Mar 2023, 9:20 am | #3 |
Octode
Join Date: Sep 2020
Location: Thetford, Norfolk, UK.
Posts: 1,731
|
Re: Sanyo TPM-2170 Mini TV / Alarm Clock / Radio
Agree totally. Q701 and Q702 are likely damaged, but personally I think the rest will be just fine.
|
27th Mar 2023, 10:04 am | #4 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,190
|
Re: Sanyo TPM-2170 Mini TV / Alarm Clock / Radio
As an aside, where did you find the complete circuit diagram of this unit? I have one but the only service manual could find was missing the last page which is the circuit of the main board.
|
27th Mar 2023, 12:51 pm | #5 |
Pentode
Join Date: Mar 2010
Location: Ipswich, Suffolk, UK.
Posts: 136
|
Re: Sanyo TPM-2170 Mini TV / Alarm Clock / Radio
Thanks folks. It looks like a major disassembly job to even get to that corner of the board where the power goes in - basically the whole thing has to be taken apart and everything removed from the chassis including the tube.
Yes, I found the same manual online with the missing back page - however, someone was selling a manual for the 2170 on eBay, and helpfully one of the pictures on the listing was a high-res photo of the circuit diagram. That photo isn't particular clear, but it's clear enough to be able to see that the circuit is the same as that for the TPM-2140, for which there is a full service manual available. |
27th Mar 2023, 1:32 pm | #6 |
Pentode
Join Date: Apr 2021
Location: Paris, France.
Posts: 235
|
Re: Sanyo TPM-2170 Mini TV / Alarm Clock / Radio
Hi Trellis,
This a recomposition of the diagram I made from two PDF parts available at radiomuseum.org. The SM is also available on electrotanya, with a lot of miising pages but at least there is an exploded view, part list and other interesting infos. However the resolution of images posted here is reduced compared to the original. |
27th Mar 2023, 3:59 pm | #7 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,190
|
Re: Sanyo TPM-2170 Mini TV / Alarm Clock / Radio
Thanks, I've now downloaded the TPM-2140 manual.
|