5 Jan
2026
5 Jan
'26
3:01 a.m.
Hi Rob,
SANYO 2SD1239 PNP POWER TRANSISTOR TO3 D1239 | eBay
UK<https://www.ebay.co.uk/itm/226368697627?_skw=Sanyo+vintage+transistor+TO3&itmmeta=01KE6WR3HZV3HY85PX27W5MHM0&hash=item34b4a0351b:g:yNQAAOSwyr9m8r37&itmprp=enc%3AAQAKAAAA8FkggFvd1GGDu0w3yXCmi1e0NqieHkQKjfFYQrMIyqfI%2BQUGEHFe6IyHxeIkeFLA840R603xiOzLKAaa4GGd%2BbeQOKa2dkhZaPMd5%2FJA6lHWNnA8pHUcQZOSdAqvrNQX9CRwtzhCB8IXy5J95zKuhJ410eIQ1QFV5rPjaITQV4rerF%2FqdmTaqByFDfc%2Bur7By0TgkQUqfg5MrfzRqKRcvjuoZzKdBiDhpYan6E00MIQwzzliUhqsGSKVYU%2FV3kvbVy3dwo1JWl9zenZKUSLF%2BlrC7XDrbjmmx2bO5fO1tdBEiX0doTPOuSCvKVyGDT6yUw%3D%3D%7Ctkp%3ABFBMnLng3PFm>
FWIW, logo is Sanyo - these devices on ebay are marked in a very similar manner
Peter
________________________________
From: Holm Tiffe via cctalk <cctalk(a)classiccmp.org>
Sent: 05 January 2026 08:52
To: General Discussion: On-Topic and Off-Topic Posts <cctalk(a)classiccmp.org>
Cc: Holm Tiffe <holm(a)freibergnet.de>
Subject: [cctalk] Re: Identifying This Component from VT100 Monitor Board
Robert Jarratt via cctalk wrote:
I asked this before a few years ago but didn't
come to a firm conclusion. The two parts are shown in this picture:
https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Frjarratt…
They are from a VT100 Monitor board. There is no schematic for my version of the board,
but a related schematic is on p58 of this schematic:
https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbitsaver…atic_Feb82.pdf>.
They are labelled Q414 and CR406, but the Feb 82 revision uses a different board and those
two parts are in TO-220 packages rather than TO-3 as here..
I have removed both of them and tested them with a DMM. Neither of them measure as two
diodes, they do not measure open circuit in any direction, so either they are both faulty
or they are not transistors (unlikely). I have found a spec for a 2SB411 at
https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Falltrans…ansistor=10279>.
This seems to be a germanium transistor. When I last asked about this I had a conversation
with Tony Duell, who was very sceptical that these could be germanium transistors, so
naturally I am very doubtful that they are 2SB411 transistors. However, in the schematic
Q414 is shown as NPN, the 2SB411 is PNP and this seems to match the way the part is
connected on my board (Collector to HORIZ GND). I am working on a reverse engineered
schematic.
Can anyone tell me what these components are so I can find a datasheet for them? Better
still a suggested replacement would be really helpful, especially if they are 2SB411s
because they seem to be hard to find.
Thanks
Rob
I don't think that it where a bigger problem to change them against
similar powerful TO220 PNPs. The cooling isn't existent or only has a
small heat sink so that the allowed 40W power loss arent used anyways.
TO220 Transistors fit easyly on TO3 Footprints.
Regards,
Holm
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