Good morning! Following this comment I made some days ago:
>Well, yesterday I was lucky enough to buy an HP-5370A in unworking condition >(just lights POWER led) for the princely sum of 57.50 Euro (and NO shipping as >it is a local buy :-) ). From same seller I got an unworking (but complete!) >5345A for 37 Euro. And also a paper 5370A service manual (14.59 Euro). And some >other cheap HP things... I have some news. As you know, I got the 5370A working as it had just a shorted tantalum and an open fuse resistor. So yesterday I went for the 5345A. I have a working unit and also a box of parts I got from the shipment-damaged unit (the one pictured here http://jvgavila.com/hp5345a.htm) First than anything else, I opened the unit to find it was missing the fan, and fan wires (which have on them 115Vac when powered!) were hanging around, touching some cards!. I was lucky to open it BEFORE powering on, as I could have ruined the unit. Hint: ALWAYS take a look inside units BEFORE powering on! My 5345A stack of parts included the fan and all needed hardware to fix it on place so I did it. Unit seemed complete except for the HPIB card empty space (unit had not that option; if somebody has an spare, I would love to buy it). One curious thing is that the ovenized oscillator is not HP but another brand. I guess it is a cheaper unit. Date on it is 1986 whilst this 5345A seems to have been made around 1982 so it appears to be as a later add-on. Anyway, I have also an spare from the parts-unit so it could be replaced if needed. Once I had visually checked the unit and replaced the missing fan, I powered the unit. All I got was fan noise (these units do really generate a _bit_ of noise!) and all '0' digits (not really; one position had a faulty segment; I swapped the 7-segment unit with the first one, which only uses the center segment). Of course, counter function didn't work. Well, at least there was no smoke! I had not opened bottom cover and I did it... to find a nice metal part loose on the bottom cover. Hint #2: open ALSO bottom cover to check for weird things! And then, checking from the bottom side, I found a suspicious thing: one connector to the input assembly was semi-unplugged!. Somebody else had obviously been there before and had tried to fix the unit (without success, I must add). So I connected it and after some vacuum-cleaner work (there were some spider rests around), I powered the unit again. This time I got a promising display, showing the ARMED sign, '*' and all '0's. Good!. So I put a 10MHz signal on INPUT A... and got a 99.xxxxxx mHz indication. So, obviously, there were some other faults on the unit. I took the Service Manual (also in paper form, which is VERY convenient to work on large foldouts) and started the troubleshooting procedure. It is curious but all my previous works on HP gear didn't need of any 'special' thing. But in the 5370A there was even an special card (I was quoted US$250 and US$1490 from two sellers for the repair kit). And in the 5345A there is lots of logic analyzer work... but, as I had a complete parted-out unit, I was confident I could fix it the fast way (i.e. replacing modules) and then perhaps working on the faulty assembly. As I wanted to check if the spare cards I had were good, I began replacing them from left to right and checking each time if there was any change in the counter operation. I put it on the CHECK position, waiting for the 100 MHz display... First six cards I had, except one, worked same way as original ones. The other one just didn't work, so I replaced it with original unit, hoping it was not the faulty card. And then, replacing next one (A9 MAIN GATE ASSEMBLY), I got the counter working :-)!!!. I checked it also with an external signal and it went right up to 500MHz with good sensitivity. NICE!!! I swapped all the cards for the original units, except A9, and counter continued to work. So I have a good set of spares (except one), just in case. Once unit was working, I looked at the poor front panel. It seems unit had been stored and transported without care and it was badly scratched. Fortunately, my parts unit front panel was very nice looking. But as it was an older version, it was not directly compatible, as power connector was completely different. Also, it had sustained some frame damage. So I took out all the knobs and nuts in both and got the aluminum plate swapped among units. Once the knobs were carefully cleaned, 'new' front panel looked really good. So this is the end of this long post (hope somebody arrives to this point ;-)!) All in all, from the three large HP units I got last Friday (5370A, 5345A, 8660B), I have already fixed two :-). The other one (8660B) has some missing parts and will sure take a lot more time (BTW, does somebody on the List have an 8660B parts-unit?) Hard work begins now... I need to fit the units in my crowded workbench :-)! Best regards, JOSE ---------------------------------------------------------------------- 73 EB5AGV / EC5AAU - JOSE V. GAVILA La Canyada - Valencia (SPAIN) - Loc: IM99SM Vintage Radio: http://jvgavila.com Vintage Test Equipment: http://jvgavila.com/testeq.htm European Boatanchors List: http://groups.yahoo.com/group/euro_ba_swap _______________________________________________ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts