HOT TAKE: if you design a laptop with a power supply that looks like this, you should go to jail.
-
the question is: what the fuck is this thing?
the label has been sadly... exploded.
I think it's either a MOSFET or a very small voltage regulator?
-
@foone Often! I repair old arcade game PCBs and the 2114 RAMs are a common failure point. The hoard of new old stock ones I've got needs to have their leads formed to fit in the board.
-
@ieure awesome. we can be "not remotely like the mainstream" buddies!
-
@foone unless its usbC
-
@RueNahcMohr god if I had a 486 Laptop that was powered by USB-C, I'd be the coolest kid in school
-
Foone🏳️⚧️replied to Foone🏳️⚧️ last edited by [email protected]
Here's the CPU.
Cx486SLC2.
This is a 50mhz (25mhz bus) "486" (it's a 386 design: 16bit bus, despite being a 32bit chip), with one entire kilobyte of L1 cache. No FPU, but it can use an external FPU. Performance is reportedly shit, but it's low-power so perfect for a laptop.Intel sued Cyrix over this thing. They lost.
-
@foone
Are there any other SOT-89 chips with "J8" as datecode or something? Those would have intact markings.Annoyingly Richtek has used "J8" for SOT-89 3.3V LDO regulators, but Richtek was likely not around when that laptop was made.
As Richtek was founded in 1998.
SeeingIt does look very regulator like, but if the 886-23255862 chip is a DC-DC controller in addition to the TL494C PWM controller already on the board.
-
@ftg sadly not, I checked. I guess I could look at the other boards?
-
Phil M0OFXreplied to Foone🏳️⚧️ last edited by [email protected]
@foone Looks like the label is "8C" and that looks like a SOT89 package. Going by Marsport it's probably a 78L05:
8C NJM78L05A NJR KQ SOT89 78L 5.0V 0.1A regulatore: From left to right, the three pins on the bottom are Out, Gnd, In. The tab connects to the middle pin, which is GND.
-
I just followed somebody who has one of these. if I can ever remember who that was, I maybe can ask them to tell me what that component is
-
@foone Stencil font seems to say:
8C
D _ (or B _)Seems like a SOT-89 linear regulator but haven’t found any direct matches with that stamp yet, wonder if the piece with the missing letter chunks is still rattling around in the case?
-
Travis Rosenbaumreplied to Travis Rosenbaum last edited by
@foone This might narrow down options, just found a bunch of candidates - most seem like regulators in this code range: https://smd.yooneed.one/code3843.html there’s a few SOT89s in the 8CD and 8CB zones…
-
Travis Rosenbaumreplied to Travis Rosenbaum last edited by
@foone Found where the picture came from, same part number: https://my.rs-online.com/web/p/voltage-regulators/7139502
-
@Zagrophyte thanks!
-
So @Zagrophyte figured out what it is: it's a 5v 100ma voltage regulator.
https://octodon.social/@Zagrophyte/113049120572694329 -
Foone🏳️⚧️replied to Foone🏳️⚧️ last edited by [email protected]
I'll have to order one and see if it fixes this laptop psu
-
@foone I thought it said Cyrix EAT for a moment
-
FantasmitaAsex :heart_ace:replied to Foone🏳️⚧️ last edited by
@foone a T2000SX
PD: At least shows the voltage
-
@lunarloony I thought the same when I first yanked the heatsink off