Monthly Archives: November 2007

PSP Power Supply Update

PSP (Original) Main Board (Power Supply)I was probing around a bit more and I’ve found the obvious problem, and it’s not the transistor. The power connector to tI can envision what happened now: an unregulated supply – works fine for just charging the battery, the current is low and the TPS65250 has a wide input voltage range. But, upon power up current demands go up, voltage drops, and this tiny connector melts because it can’t handle the current. It surprised me this would happen before the input fuse blew – bad design I guess, should have used a connector rated for higher current since the connector is on the supply side of the fuse. It took longer to find since I never suspected this, but, was fairly easy to fix. Next time check the simple things first.

NEC Versa LX secondary battery

battery2Battery uses weird Sony Energytec US103463 prismatic cells — haven’t found a suitable replacement cell — let me know if you have a source; until then, it’s filed under “battery”.

I love that laptop, and it’s great battery life. I kept asking myself why no-one makes new slower, low power laptops with new technology (except they’re moving towards it again with the XO and eeePC). The versa gave me 7 hours of portable computing (or more with standby), while most new laptops give you 3 hours. I couldn’t find anything smaller than the versa for a good price when I got a new laptop in 2005.

PSP Power Supply

PSP (Original) Main Board (Power Supply)Tom gave me his PSP after frying it by using the wrong powersupply. The micro fuses were okay, so onto the SMPS! It’s self contained – up in the top left corner in the picture, but, on the other side of the board. I didn’t take a picture of that size for some reason. So, this supply is based on a Texas Instruments Power Management IC, TPS65250. Anyways, closest datasheet I could find online was for the TPS65050 series. I assume the rating are simply a bit different, or this is OEM’d. I’m thinking right now that the main switching transistor is shot…and since those SMD transistors are basically impossible to identify – since they never seem to have any text on ’em – I just pull random ones off of old broken computer motherboards and assume they’re close enough….they all have been so far.