HP Forum Archive 20

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48G mod. after 15 years. Message #1 Posted by Lyuka on 19 Oct 2011, 3:05 a.m. Hi Though I have an HP 50g, I've repaired the 15 years old 48G from a kind of sentiment and nostalgia recently. Then upgraded its memory to 128KB and additional 128KB with memory backup at port 1. Actually, I prefer 48G's key pads than that of 50g. Lyuka

Re: 48G mod. after 15 years. Message #2 Posted by bluesun08 on 19 Oct 2011, 7:34 a.m., in response to message #1 by Lyuka Is it possible also to implement 50g-Rom?

Re: 48G mod. after 15 years. Message #3 Posted by Lyuka on 20 Oct 2011, 4:59 a.m., in response to message #2 by bluesun08 AFAIK, It's impossible as the processor differs.

Re: 48G mod. after 15 years. Message #4 Posted by Nacho on 19 Oct 2011, 7:52 a.m., in response to message #1 by Lyuka As always, fantastic work and explanation. 2 months ago I received a non working 49g , took its display and installed it into my 48G+ and changed also the cap... full 48 working machines :) regards

Re: 48G mod. after 15 years. Message #5 Posted by Lyuka on 20 Oct 2011, 5:07 a.m., in response to message #4 by Nacho Thanks Nacho, I'd like to see the LCD transplantation. It's also interesting. Is the LCD of the 49g completely compatible to 48g? Regards, Lyuka

Re: 48G mod. after 15 years. Message #6 Posted by Nacho on 20 Oct 2011, 5:41 a.m., in response to message #5 by Lyuka Quote: Thanks Nacho, I'd like to see the LCD transplantation. It's also interesting. Is the LCD of the 49g completely compatible to 48g? Regards, Lyuka Hello Lyuka, The display is P&P but far better with the high 49g contrast. I will post a picture later. Regards

Re: 48G mod. after 15 years. Message #7 Posted by Ed Look on 19 Oct 2011, 9:52 p.m., in response to message #1 by Lyuka Absolutely impressive! Was it difficult to open the case? And, the holes are CLEAN after you desoldered and removed the chip and capacitor! Very neat job. I suppose this was not done with tools normally found at home, right?

Re: 48G mod. after 15 years. Message #8 Posted by Lyuka on 20 Oct 2011, 5:45 a.m., in response to message #7 by Ed Look Thanks Ed, It's fairly easy to open the case if you use a special tool for the 'pioneer' --- A BUTTER KNIFE! :-) To pull out the four heat stakes behind the [1][2][3] keys, I had used it as a leverage to make the bottom of the case apart. FYI you'd better have its edge rounded and polished not to harm the inside part of the housing. Regards, Lyuka

Re: 48G mod. after 15 years. Message #9 Posted by Thomas Chrapkiewicz on 19 Oct 2011, 11:16 p.m., in response to message #1 by Lyuka Nice work (and documentation). How did you remove the 32k memory? Did you use chipquik or solder braid? Regards, TomC

Re: 48G mod. after 15 years. Message #10 Posted by Lyuka on 20 Oct 2011, 5:57 a.m., in response to message #9 by Thomas Chrapkiewicz Thanks TomC, Exactly! I used CHIP QUIK SMD (pdf) like ultra low melting point solder to remove the SOP RAM. FYI it's available online at DigiKey. Regards, Lyuka

Re: 48G mod. after 15 years. Message #11 Posted by Paul Berger (Canada) on 20 Oct 2011, 2:35 p.m., in response to message #9 by Thomas Chrapkiewicz I have removed several SOIC package chips safely and cleanly by starting at one corner and heating the pins and the lift it away from the board using something thin like a sewing needle. Usually if you remove heat simultaneous to lifting the pins, you can get away with just running the needle under the pin and by the time it drops again the solder has cooled enough that it does not stick again. Needles work well because they are thin and you can work your way down the case with it, and they don't lift the pin much so as to minimize bending. You could do the same thing with a thin blade but that doe not work so well if the chips are densely packed on the board.

Re: 48G mod. after 15 years. Message #12 Posted by bill platt on 20 Oct 2011, 10:32 a.m., in response to message #1 by Lyuka Another great tid-bit to be used one day. Chip Quik! Great idea!

Re: 48G mod. after 15 years. Message #13 Posted by Dave Shaffer (Arizona) on 20 Oct 2011, 12:44 p.m., in response to message #12 by bill platt Quote: Chip Quik! Great idea! Sounds like the latest, greatest cookie dough to hit the market!

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