From: Doug Cotton Subject: Regulator Date: Sat, 10 Jul 1999 18:25:08 -0400 A quick note: I saw this discussion thread on FIDO (I can read but I can't post), and thought I might shed some light on why some folks can't seem to locate the zener diode described in the original quote by Mark Fellows. That part only exists on the version 1 RAMLink (the ones with the 'brick' power supplies.) That version had a regulated power supply, whereas the version 2 model uses an unregulated 'wall-mount' supply. This change necessitated that we completely redesign the power/charging circuitry. So if you have a version 2 RAMLink, you won't find this part. Version 2 may have a resistor that servers a similar purpose (if I recall correctly), but there's little chance of that being bad. Version 2 will also exhibit a slightly higher charging voltage (while charging and under load) than a version 1 does, again due to the changes in the recharging circuitry. Doug Cotton CMD Support support@cmdweb.com --------------------------------------------------------------------- RAMLINK & BBU FIX From : MICHAEL KELLEY --------------------- I pulled the following message off of the Internet Usenet Newsgroups, and tried it on a friends RAMlink that we have been having trouble with for over a year. ---text quote--- I've had a RAMLink unit for about 4 years and the battery backup system on it has never worked. Just this week I received a letter from Mark Fellows at CMD. He says: "Over the last few years I have repaired RAMLinks with similar prob- lems to yours. In each case replacing ZNR1 (a 1N5232B zener diode) on the mother board cured the problem and allowed [it] to charge up to 6.4v" I fitted the new diode and the current immediately went from 112mA to 160mA and the voltage from 4.79 to 6.98 volts. (Measured across the leads to the battery with battery disconnected). If your RAMLink BBU isn't 100% this diode change may well fix it. ---end quote--- Suffice it to say that my friends RAMLink went from 5.7 volts to 7.2 volts, and the battery came to a complete charge within 24 hours. Before, it never went above 5.2, and even a small brownout caused problems. We then loaded the 4 meg unit up with files, and unplugged it. 13.5 hours later, he powered the system up, and all the files were still there, in- tact in the RAMlink. 13.5 hours!! This is with a 6 volt, 6 amp battery. We have ordered a 10 amp battery, and will see how well it does in the same test. He unplugged the system again, but after an addition 6 hours the data was lost. Somewhere around 5 amps, the RAMlink battery loses power quickly, and subsequently files in the unit. If any of you have similar problems with your RAMlink, I HIGHLY recom- mend this fix. 75c part and MAYBE a half hour work. RAMlink Battery (cont.) FROM: RidgeRunr (Michael Kelley) (Information posted on Q-Link) -------------------------------- In an earlier post, GR MORANEC mentioned a part for RAMCARD II own- ers that would help fix improper battery recharging. I spoke to CMD Doug at Creative Micro, and the part is R49, located near the battery jack. It needs to be a 5 ohm, 1/4 watt resistor, with a 5% tolerance (gold band). Between this information and the previous post for earlier RAMLink owners, a variety of battery back up problems might get cured. Enjoy!