Toshiba dvd/hd recorder RD-88DT-K-TB dead.

[PlainBill]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Thanks PlainBill, Ive tested the zener as you suggest & im getting a reading of 1.1 both ways so whats next?.,,,,many thanks.

1.1 What? Ohms? In circuit or out of circuit? Where is it; I haven't been able to locate it on the pictures? Details like this are important, and that certainly sounds like the zener is bad.

PlainBill

[froggy]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Ooops sorry PlainBill I meant to say its out of circuit, With the meter set at 200 ohms the reading was 1.1 which i presume is ohms, The zener board position is D2107 (see pic) sorry its a little bit fuzzy.,,,cheers.

[tom66]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Would seem bad then, but could you check again on the diode range?

The problem is going to be identifying the voltage of the replacement to be used. It might be possible to infer it from the circuit, but a schematic is often necessary. Finding one could be difficult.

Edit: Spoke too soon. Here it is: http://elektrotanya.com/toshiba_rd-8.../download.html (Not an exact match to your model, but Toshiba list the RD-88DT series as being the same as RD-88DT-K-TB; I'm guessing the -K-TB is only a variant or something.)

There's a layout on page 61 and schematic on page 49.

The part number for D2107 is 27BSB-T26. A 27V Zener diode. Member of the BZX series, datasheet here.

It would seem the diode is involved in limiting the gate drive to the MOSFET. I would not have guessed that from the board or its position.

[froggy]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Tom you are a star!, ive now d/loaded the schematics & hopefully will be able to find the culprit, i`ll keep you posted,,,,,,Many thanks.

Just one other thing, the link to the BZX datasheet takes me to datasheets for BZV series I was just wondering why?.

[tom66]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Just one other thing, the link to the BZX datasheet takes me to datasheets for BZV series I was just wondering why?.

Ah yeah, my error. BZV is surface mount and would be a bugger to solder to a through hole PCB. Here's the BZX datasheet.

But almost any 1/2W zener diode would probably work.

[Didier13600]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Does anyone of you has the diagramm of this power supply.? My recorder doesn't power up (no output tension)
Thanks

[tom66]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Does anyone of you has the diagramm of this power supply.? My recorder doesn't power up (no output tension)
Thanks

Here: http://elektrotanya.com/toshiba_rd-8.../download.html

[froggy]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Right, after a bit of waiting I finally got the correct fet, So now ive changed that as well as a faulty zener, Ive now been testing the outputs to the 34 pin outputs as suggested by PlainBill, (I take it I test them on DC), On pin 34 im getting 20.6v (should be EV+ 33V), then from 32-30 im getting 5.7v (should be AL+2.8v), Then from 29-24 im getting 0v (should be EV+12v), Ive not checked any further as its very fiddly so im going to make up a finer probe tomorrow & go through the lot, But so far these figures im getting seem odd, Also what do the abbreviations `EV & AL`mean?, Looks like I picked on the wrong thing to learn on!.,,,,cheers.

[tom66]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Right, after a bit of waiting I finally got the correct fet, So now ive changed that as well as a faulty zener, Ive now been testing the outputs to the 34 pin outputs as suggested by PlainBill, (I take it I test them on DC), On pin 34 im getting 20.6v (should be EV+ 33V), then from 32-30 im getting 5.7v (should be AL+2.8v), Then from 29-24 im getting 0v (should be EV+12v), Ive not checked any further as its very fiddly so im going to make up a finer probe tomorrow & go through the lot, But so far these figures im getting seem odd, Also what do the abbreviations `EV & AL`mean?, Looks like I picked on the wrong thing to learn on!.,,,,cheers.

This is an odd power supply, but I suspect most of the rails are unregulated - that is, the voltages are only nominal. I'd try plugging it in to see if it works.

[froggy]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

This is an odd power supply, but I suspect most of the rails are unregulated - that is, the voltages are only nominal. I'd try plugging it in to see if it works.

Ive tried plugging it all in & im getting nothing lighting up, ie: still dead.

[tom66]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Ive tried plugging it all in & im getting nothing lighting up, ie: still dead.

Hmm, odd... You can measure the voltages on the cathode of the diodes. Check if any voltages appear significantly out of spec; there may be a bad cap or a problem with the power supply.

[Didier13600]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Thanks Tom i'll do me best to troubleshoot this power

[dan8139]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

I know it's over a year later, but just repaired one of these machines where the PSU was 'dead', fault was shorted schottky diode d2204. Hopefully this helps someone!

[damianr]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

I know it's over a year later, but just repaired one of these machines where the PSU was 'dead', fault was shorted schottky diode d2204. Hopefully this helps someone!

I change this d2204 and d2205 but when i connect everythink together is work just 5 secend and again is problem with this d2204 and d2205. Can You help me please

[SlySven]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

I've just got one of these to look over and it has a whining, (overloaded ?) PSU and the 32/12/main 5 volt supplies are way down (5V is actually at 1.6). No obvious bulging caps, but thanks to tom66's Elecktrotanya link (I've used that site before but could never remember the name!) I now have something to help me look over the PSU and associated components...

Thanks Bob!

[Agent24]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

I'd check the rectifier diodes, probably one of them is shorted.

[cristianmoi]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Un saluto a tutti, ho la stessa scheda elettronica morta. Per caso qualcuno mi può dare lo schema elettrico di questa scheda?

[Unspun01]

Re: Toshiba dvd/hd recorder RD-88DT-K-TB dead.

Per caso qualcuno mi può dare lo schema elettrico di questa scheda?

Un saluto!

https://elektrotanya.com/toshiba_rd-.../download.html