[RASMB] XL-A "waiting for speed" forever

[John Gunther]

Hi Alessandro,

It sounds like the ultracentrifuge has hung. When this happens one could 
shut down everything. Recycle the power and start over.
When you do this use the stop button on the 'fuge. When the rotor comes 
to a rest wait 30 minutes to allow the diffusion pump to cool*.
You do not have to vent the chamber for a short power cycle on the fuge. 
Turn off the fuge, (after the 30 minute cooling period), for about 10 
seconds.
Then turn it back on. It should not vent the chamber. It will restart 
the vacuum pump and continue to pull down the chamber.

Cycle the power on the PC and launch you AUC app. (cold start the PC by 
shutting down and turning the power off)

If the fuge won't respond to the stop button one could cycle the fuge 
power while it's running at 3k as a last resort. This IS NOT recommended 
with a hot diff pump.

The bottom line is the fuge has NVRAM (non-vol-ital ram) on the 
instrument control board, and the CRT control board. These "chips" have 
a battery on board the chip to hold memory when the power is off. This 
battery is a Lithium battery with a life span of 10 years or less 
(sometimes more). If your machine is more than 10 years old, and these 
chips have not been replace, it is likely your chips are getting bad 
(the internal batteries are dying). You can buy these chips from Beckman 
Coulter however they are expensive from them. They can be purchased from 
electronic part suppliers for around $30 each US.
If you have a qualified electronic person they could replace them. These 
chips are in sockets and are intended to be replace.
There is a clock chip on the CRT control board that needs to be replace 
for the same reason, a dead battery. This resolves itself as the date on 
the fuge appearing as ??/??/??. The time is also incorrect on the fuge. 
(not the PC) The clock chip can be more complicated as sometimes it is 
not in a socket.

If you are interested in doing this, I can help you. If you don't feel 
comfortable doing this, call your Beckman Coulter service rep.

Overspeed disks are expensive and would likely not do anything for this 
problem.

John Gunther
Rocky Mtn SIMS, LLC


* allowing the diff pump to cool will reduce the possibility of free 
vaporous diff pump oil condensing on the optical components.

On 2/11/2020 7:24 AM, Marius Schmid wrote:
> Dear Alessandro,
>
> If I remember correctly, I might have seen an error like this in the 
> past. But I am not entirely sure if it was caused by the overspeed 
> disc of the rotor or an malfunction of one of the control boards. Did 
> you try to exchange the overspeed disc of the rotor? There might be a 
> problem with the magnets on the overspeed disc and the hall sensor.
>
> best wishes,
> Marius
>
> Am Dienstag, 11. Februar 2020, 14:40:59 MEZ hat Alessandro S. 
> Nascimento <asnascimento at ifsc.usp.br> Folgendes geschrieben:
>
>
> Dear RASMB members,
>
> we are having a problem with our XL-A. I've searched in the list and 
> the possible solutions I could find did not solve the problem.
>
> Once the experiment is set up, with stabilized temperature and vacuum 
> (0 micron) running at 3000 rpm the instrument status keeps as "waiting 
> for speed" while the instrument is already stabilized @ 3000 rpm.
>
> We tried to rapidly remove the white jumper and plug it again and also 
> tried to setup a non-zero velocity with the door open (forcing a drive 
> diagnostic). Those suggestions appeared in the list in the past. None 
> of these could restore the sync between the instrument and the software.
>
> Any clues on what could be going on?
>
> I thank in advance,
>
> -Alessandro
>
> -- 
> ********************************************************
> Alessandro S. Nascimento
> Professor
> São Carlos Institute of Physics (IFSC)
> University of São Paulo (USP) - Brazil
> E-mail: asnascimento at ifsc.usp.br <mailto:asnascimento at ifsc.usp.br>
> Phone: +55-16-3373-8709
> ********************************************************
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