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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
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9th Jun 2022, 11:15 pm | #21 |
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Re: Toshiba RD-XV47 DVD/VCR Combo.
I'll try heating and freezing. Am away for a few days, will look at it when I get back.
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11th Jun 2022, 4:12 pm | #22 |
Hexode
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Re: Toshiba RD-XV47 DVD/VCR Combo.
hi michael, is it possible to upload a picture of the power board on this, may help jog my memory for you .regards brian
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20th Jun 2022, 8:29 am | #23 |
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Re: Toshiba RD-XV47 DVD/VCR Combo.
Here are some pictures of the power supply. There are no components under the board.
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20th Jun 2022, 4:49 pm | #24 |
Octode
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Re: Toshiba RD-XV47 DVD/VCR Combo.
This might be a stupid question but when the set has reverted to standby does the handset switch it back on and does it then stay on normally. I ask this as we have one of these sets at our local museum and if it gets put into standby by the handset before removing the mains power, next time it's switched back on it remembers this and thus after a few seconds reverts to standby. It has to be manually switched off at the set in order for it to power up again from the sets controls. Then again maybe thats a fault with our museum model.
Dave
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20th Jun 2022, 4:57 pm | #25 |
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Re: Toshiba RD-XV47 DVD/VCR Combo.
I'd check the +5v supply is exactly 5v- a slight drop to 4.8v and the thing won't work.
Mind you I had one that did this. I changed the power supply with a known good one and it still switched off. Eventually I gave up on it after many hours of trying. |
20th Jun 2022, 7:44 pm | #26 |
Hexode
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Re: Toshiba RD-XV47 DVD/VCR Combo.
hi michael, from what i can see on the pictures, i think the one diode we had trouble with is located central to a group of three regulators [unable to make out the cct ref ] but the diode is in line wth d1147 [unable to read the cct ref] is the culprit . in5397 even if it checks o/k on the meter change it [its 600v piv and 1.5 amp ] from memory . i have been retired a few years now but thats what looks familiar to me it may well have been d1147 though.
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23rd Jun 2022, 9:57 pm | #27 |
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Re: Toshiba RD-XV47 DVD/VCR Combo.
None of those suggestions worked, so I'm calling it a day.
Unless of course anyone has the magic cure for it! |
28th Jun 2022, 8:04 pm | #28 |
Heptode
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Re: Toshiba RD-XV47 DVD/VCR Combo.
No magic cures but there is a very crafty (cheap?) global short circuit / low output protection circuit/system for nearly all power supply rails including regulated outputs from other boards! Might be worth checking to see if this is being activated.
From power 5/10 board 'Safety1' signal line connects to boards Power 7/10 and 9/10 as well as the power supply board. Many diodes connect 'Safety1' to each supply in a wired-OR fashion. Power 5/10 board has the main system control processor IC1501 and 'Safety1' is connected to Pin 84 with a 10k pull-up resistor (R1763) to Always +3.3V. So it looks as if any supply rail disappears the respective diode will turn on to assert pin 84 low, where the CPU will then try to turn off the system. 'Safety1' should stay high all the time so could be worth checking this is not triggering shutdown. Rich
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29th Jun 2022, 1:21 pm | #29 |
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Re: Toshiba RD-XV47 DVD/VCR Combo.
The diodes mentioned are 1N4003s and have an annnoying habit of becoming leaky. Trouble is you need to take the whole thing to bits (again) and change them all. Then you find it's the micro...
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30th Jun 2022, 11:23 am | #30 |
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Re: Toshiba RD-XV47 DVD/VCR Combo.
I've finally found out what was going on.
When I've been testing it, I had the covers off including the back, although I covered the deck to stop light getting into the sensors. On the back panel is a fan, when the back is removed it the fan is not connected. When this was refitted, it worked. |
30th Jun 2022, 11:28 am | #31 |
Octode
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Re: Toshiba RD-XV47 DVD/VCR Combo.
Great news Michael! I can just imagine how you must feel now.
You got there in the end, that’s the main thing. Peter |
30th Jun 2022, 11:42 am | #32 |
Octode
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Re: Toshiba RD-XV47 DVD/VCR Combo.
It's often the simplest of things that trip us up and something you would not consider as it's not a desktop pc.
Dave
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30th Jun 2022, 11:59 am | #33 |
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Re: Toshiba RD-XV47 DVD/VCR Combo.
Presumably that wasn't the original fault for which you took it apart in the first place though - hopefully one of the numerous speculative component changes has fixed the original fault.
Your subsequent problem is one of those cases where something helpful, like an error message or error code (because the fan was not detected spinning) would have saved you a lot of grief. Well doing getting it going, I admire your sheer determination to fix it. |
30th Jun 2022, 3:25 pm | #34 |
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Re: Toshiba RD-XV47 DVD/VCR Combo.
The thing is its a two wire fan, there's no 'sense' wire so presumably it only detects that the fan has been connected, not whether its spinning or not.
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30th Jun 2022, 4:58 pm | #35 |
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Re: Toshiba RD-XV47 DVD/VCR Combo.
Which is no doubt why you thought it was OK to disconnect it (since it did not have a third 'tacho' wire). We live and learn.
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30th Jun 2022, 7:33 pm | #36 |
Hexode
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Re: Toshiba RD-XV47 DVD/VCR Combo.
well done michael ,good to know alls well now
brian |
1st Jul 2022, 11:50 am | #37 |
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Re: Toshiba RD-XV47 DVD/VCR Combo.
You live and learn - I'd have thought a 2-wire fan wouldn't matter if disconnected. Glad you've sorted it out at last - these can be horrendous things when they fail. Three sockets on the VCR deck (like everyone else fitted) and they would be a far better machine to work on. Thanks Funai!
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