Transistor Replacement

[AndiGer]

(04-18-2022 11:51 AM)teenix Wrote:  Hi all,

I'm looking at a HP-97 for someone with a dim display and it needs one or two transistors replaced. One is a current bypass for the charger which has the casing face detached, probably from overload and the other one supplies current to the anode drivers.

1853-0393 and 1853-0374 both PNP's.

Funnily enough, these parts, and parts I've searched for in the past using the HP X-Ref file, yielded no matches.

I've seen previous posts discussing parts matches but I cant locate them.

Any ideas - probably general purpose PNP's will do - 2N2907 etc.

cheers

Tony

Correct - 2N2907 will do. Replaced on the keyboard PCB once and noted inside my printed service manual :-).
N.B. 1854-0071 replaced by 2N2222

Andi